Evaluation of a Gliding Arc Discharge Non-thermal Atmospheric Pressure Plasma Device for Orthodontic Bonding

Abstract

The purpose of this study was to investigate the effect of gliding arc discharge non-thermal atmospheric pressure plasma with N₂ carrier gas on surface chemical modification for adhesion improvement. The shear bond strength between the orthodontic adhesive resin and plasma-treated stainless steel surface improved slightly, although the surface free energy of the stainless steel samples increased from 73.6 mJ·m⁻² to 112.9 mJ·m⁻² mainly due to an increase of the dipole component (γ_S^p) and partially due to an increase of the hydrogen bond component (γ_S^h). This is partly because the metastability of the stainless steel surface was stabilized by immediate hydration or adsorption of water on the highly hydroxylated stainless steel surfaces. However, surface cleaning and hydroxylating efficacy of the handheld device was determined to be superior to those of other surface cleaning procedures, particularly in terms of intraoral applications. The technique may be potentially employed in establishing M-S coordinate bonds in dental precious metals and related alloys.